Mars Express to rendezvous with Martian moon

July 16, 2008,

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, is one of the highest-resolution pictures so far of the Martian moon Phobos. The image shows the Mars-facing side of the moon, taken from a distance of less than 200 kilometres with a resolution of about seven metres per pixel during orbit 756, on 22 August 2004. This colour image was calculated from the three colour channels and the nadir channel on the HRSC. Due to geometric reasons the scale bar is only valid for the centre of the image. Credits: ESA/DLR/FU Berlin (G. Neukum)

(PhysOrg.com) -- Scientists and engineers are preparing ESA’s Mars Express for a pair of close fly-bys of the Martian moon Phobos. Passing within 100 km of the surface, Mars Express will conduct some of the most detailed investigations of the moon to date.

The series of fly-bys will take place between 12 July and 3 August. During the second encounter, the spacecraft will fly within 273 km of the surface. Six days later, Mars Express will close to within just 97 km.

Although the Red Planet itself has been studied in detail, very little is known about the origins of its moons, Phobos and Deimos. It is unclear if the moons are actually asteroids that were captured by Mars’s gravity and never left its orbit. Another possibility is that Phobos and Deimos are actually surviving planetesimals, bodies which formed the planets of the Solar System. They may also be remnants of an impact of a large object on Mars.

As Mars Express closes-in on Phobos, the data gathered will help scientists answer these questions.

Mars Express has flown close to Phobos in the past, but this is the first time that the spacecraft will be less than 100 km from the moon. To achieve this proximity to Phobos, spacecraft operations engineers and scientists have been working together to optimise the trajectory of Mars Express to obtain optimum science results – this is not the case for routine fly-bys.

As it flies by at a distance of 97 km, Mars Express will image areas of Phobos that have never been glimpsed before. The High-Resolution Stereo Camera (HRSC) on board the orbiter will take pictures of the moon’s surface with the highest resolution possible, in colour, and in 3-D.

The data obtained will be added to a digital terrain model (DTM). This DTM will help scientists visualise what it would be like to stand on the moon’s surface by calculating its topography, or the elevation of its surface.

The camera may also capture an image of the intended landing site for Russia's Phobos-Grunt mission, due for launch in 2009. The manoeuvres required to observe this site are an operational challenge, and the activity involves close cooperation between ESA mission scientists, the flight control team and flight dynamics specialists.

The Visible and Infrared Mineralogical Mapping Spectrometer, OMEGA, the Planetary Fourier Spectrometer, PFS, and the Ultraviolet and Infrared Atmospheric Spectrometer, SPICAM, will also gather details on the surface composition, geochemistry and temperature of Phobos.

The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) will collect information during two flybys (23 and 28 July) on the topography of the moon’s surface and on the structure of its interior.

The Energetic neutral atoms analyser, ASPERA will study the environment around Phobos, in particular the plasma that surrounds the moon and also the interaction of the moon with the solar wind.

During the second fly-by, all efforts will be concentrated on accurately determining the mass of the moon using the Mars Radio Science experiment (MaRS).

(PhysOrg.com) -- Mars Express closed in on the intriguing martian moon Phobos at 6:49 CEST on 23 July, flying past at 3 km/s, only 93 km from the moon. The ESA spacecraft’s fly-bys of the moon have returned its most detailed ...

ESA's Mars Express will skim the surface of Mars' largest moon Phobos on Wednesday evening. Passing by at an altitude of 67 km, precise radio tracking will allow researchers to peer inside the mysterious moon.

(PhysOrg.com) -- Today Mars Express began a series of flybys of Phobos, the largest moon of Mars. The campaign will reach its crescendo on 3 March, when the spacecraft will set a new record for the closest pass to Phobos, ...

Mars' moon Phobos has already been extensively observed – this image is just one example, taken in 2009 – so its occultation of Mars Express on 28 April 2014 is not expected to yield dramatic discoveries.

Astronomers reveal a new high resolution map of the magnetic field lines in gas and dust swirling around the supermassive black hole at the centre of our Galaxy, published in a new paper in Monthly Notices of the Royal Astronomical ...

Using the Atacama Large Millimeter/submillimeter Array (ALMA) to observe an active galaxy with a strong ionized gas outflow from the galactic center, a team led by Dr. Yoshiki Toba of the Academia Sinica Institute of Astronomy ...

The planet Mars has fascinated scientists for over a century. Today, it is a frigid desert world with a carbon dioxide atmosphere 100 times thinner than Earth's. But evidence suggests that in the early history of our solar ...

An international team of astronomers, including Professor Bob Nichol from the University of Portsmouth, has confirmed the discovery of the most distant supernova ever detected – a huge cosmic explosion that took place 10.5 ...

0 comments

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.